Endocrine Abstracts

JOINT2598

Pituitary stalk interruption syndrome (PSIS) is diagnosed on the basis of clinical manifestation and the characteristic picture of pituitary gland on MRI. PSIS may represent an isolated morphological abnormality or may be accompanied by other structural defects of the midline of the brain. In terms of endocrine evaluation, it is characterised by a wide spectrum ranging from the absence of significant endocrine abnormalities to combined pituitary hormone deficiency (CPHD). In patients with PSIS, it is difficult to predict when hypopituitarism (isolated or CPHD) will become apparent. The aim of this study was to characterize the correlation between the pituitary hormonal pattern and the MRI features in 50 children with PSIS.

Results: Out of 50 subjects, 30 (60%) were diagnosed with CPHD, while 18 (36%) with isolated GHD. In 1 boy with vasopressin deficiency, endocrine function of the anterior pituitary was normal (2%), while in 1 girl (2%) who remains under the neurological care due to cerebellar vermis dysplasia, no endocrine abnormalities were found. Five patients out of 50 (10%) were diagnosed with arginine vasopressin deficiency. GHD was diagnosed in 47 children (94%). It should be noted that one patient presenting with IGF-1 and GH below normal (0.05 ng/ml) has achieved age-appropriate growth (90-97c) was not classified as a child with GHD. MRI examination showed anterior pituitary hypoplasia in 45/50 children (90%), none of them presented with aplasia. Agenesis of the pituitary stalk was observed in 13/50 patients (26%) and hypoplastic pituitary stalk in 36/50 patients (72%). The ectopic posterior pituitary lobe was diagnosed in 45/50 subjects (90%), while in 5 patients the posterior lobe was not visible. Septo-optic dysplasia was diagnosed in 21/50 patients (42%): 3/3 criteria – 9 children, 2/3 criteria -12 children. In the group with pituitary stalk agenesis, isolated GHD was diagnosed in 15.4% patients, whereas CPHD was presented in 84.6% cases. In the group with pituitary stalk hypoplasia isolated GHD or no abnormalities in anterior pituitary were diagnosed in 47% patients whereas CPHD was observed in 53% cases. In 15/16 children (94%) with optic nerve hypoplasia were found to have CPHD. Diabetes insipidius was diagnosed exclusively in the 5 patients in whom the posterior pituitary lobe was not visualised 1. Picture of pituitary stalk agenesis and optic nerve hypoplasia in MRI may determine the severity of endocrine disorders of the anterior pituitary. 2. The absence of the posterior pituitary correlates with the development of diabetes insipidus.